1. Field of the Invention.
This invention relates in general to a relational database management system, and in particular, to a multi-threaded, multi-tasking architecture for a relational database management system.
2. Description of Related Art.
The purpose of this invention is to enable a parallel processing relational database management system (RDBMS) to execute on both WINDOWS NT(trademark) and UNIX MP-RAS(trademark) operating systems for both symmetric multi-processing (SMP) and massively parallel processing (MPP) hardware architectures. The problem for the RDBMS is to design it in such a manner as to allow the RDBMS to execute independent of operating system models, i.e., regardless of whether the operating system provides a thread model (WINDOWS NT) or process model (UNIX MP-RAS).
This is significant because the RDBMS was originally designed to work only with process models. Given this consideration, and the demand for the RDBMS to work under a thread model (WINDOWS NT); it can be seen that the RDBMS needed to be operating system independent. In other words, the RDBMS need to be designed in such a manner that a separate version of the RDBMS need not be developed and maintained for every new operating system or platform that becomes available.
To overcome the limitations in the prior art described above, and to overcome other limitations that will become apparent upon reading and understanding the present specification, the present invention discloses a parallel processing architecture for a relational database management system (RDBMS) that supports both a process model operating system and a thread model operating system. The RDBMS is implemented as a shared nothing, single database image utilizing Parallel Database Extensions (PDEs) that insulate the RDBMS from the specifics of the operating system and that provide the necessary techniques for accessing common memory segments.
An object of the present invention is to provide more efficient usage of parallel processor computer systems. Another object of the present invention is to provide a foundation for multi-threaded, multi-tasking relational database management systems. Still another object of the present invention is to provide a portable relational database management system that can run under different operating system.